(a) Field of the Invention
The present invention relates to a transceiver module. More particularly, the present invention relates to a transceiver module packaged in a passive alignment scheme using an optical bench, and the optical bench used in the transceiver module.
(b) Description of the Related Art
Recently, exchange of information (e.g., image, data, voice) has become massive, and Internet communication has been widespread. Accordingly, super high speed information communication networks using optical fiber are rapidly being developed for high speed information transmission within and between countries.
To construct an optical communication network, optical fiber which is an medium for an optical signal, an optical transceiver module which converts an optical signal into an electrical signal or converts an electrical signal into an optical signal, and other functional elements for distributing, amplifying, and modulating a signal are essentially needed. Among these elements, the optical transceiver module is very important in constructing the optical communication system.
In this optical transceiver module, elements like a laser diode, a photodiode, and an optical fiber are aligned with micron precision. There are two types of alignment schemes for aligning the laser diode, the photodiode, and the optical fiber: an active alignment scheme and a passive alignment scheme.
The active alignment scheme is for fixing the laser diode at a certain position at which an amount of light incident to the optical fiber is maximized, by welding or using an epoxy adhesive while driving the laser diode. The passive alignment scheme is for fixing the laser diode without driving it. As examples for the passive alignment scheme, there are a scheme for aligning by recognizing positions of the laser diode and the optical fiber with an image processing device, a flip-chip bonding scheme using a phenomenon of minimization of surface tension of melted metal, and a scheme for minutely processing a silicon bench in a three-dimensional shape and mounting various optical elements having different functions on the silicon bench by using semi-conductor substrate photolithography.
This optical transceiver module has technical problems in aligning the optical fiber and the laser diode with micron precision, and needs a large amount of investment for installations necessary for mass production. Accordingly, the optical transceiver module is expensive and has drawbacks in that it costs a great deal to put the optical communication network in place.
Therefore, a transceiver module that is easy to manufacture and is able to be mass produced at a low cost by reducing the number of optical parts is urgently needed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.